David Cameron's attempt to mollify his Eurosceptic backbenchers isn't the simplest scheme – but given the complexities of coalition politics, it never could be.
The plan, roughly speaking, is this: the government (or the Conservative bit of it) has published a handy draft bill, which they hope a backbencher will adopt. If it gets far enough through the parliamentary process, they'll "try" to give it the government time it would need to become law.
It's not a scheme that has won round many Conservative backbenchers. The main gripe they seem to have is they don't seem all that convinced a Private Member's bill (the name for a bill introduced by a backbencher) will actually pass.
So: are they right? We dug out the data since 1979 on government and private members' bills, and how many of them got royal assent. The results are below:
The short answer is Conservative backbenchers are right to be worried. On average, for any given year between 1979 and 1990, the chances of a government bill gaining royal assent was 94%.
For private members bills, it was just 11%. So government bills are more than eight times as likely to become law. Now, things might be different for a bill that's being given a nod-and-a-wink by the largest party in government.
But, given the success rate in recent years has been well below even that average, perhaps Tory backbenchers are right to have their reservations.
The full data on the number of government and private members' bills tabled each year since 1979 – and how many got through – is below. What else have you spotted in there? Let us know in the comments below.